The objectives of these investigations are the understanding of the chemistry and metabolism of lipids in testes, epididymis and spermatozoa - particularly in biosynthesis, interconversion and oxidation of fatty acids and factors (such as age, hormones, diet, drugs) which influence these processes. These studies seek to understand the relationship of cellular structure to these processes and the role of the polyenoic acids in the physiological function of the male reproductive system. Experiments with intact animals (using intratesticular injection of substrates) and in vitro preparations will be used with radioactive substrates to elucidate these reactions. Methodology includes the use of column, thin-layer, gas and high pressure liquid chromatography, liquid scintillation beta spectrometry, gas radiochromatography, chemical degradations and separation of testicular cell types by elutriation centrifugation.